Evolving Dark Energy or Evolving Dark Matter?

TL;DR

This paper demonstrates that current cosmological data can be explained by a model where a small portion of dark matter has an evolving, oscillating equation of state, offering a more physically consistent alternative to dark energy models with $w<-1$.

Contribution

It introduces a novel interpretation of cosmological data suggesting dark matter's equation of state evolves and oscillates, challenging traditional dark energy paradigms.

Findings

Data compatible with evolving dark matter equation of state

Oscillating dark matter model fits observational constraints

More physically plausible than phantom dark energy models

Abstract

We show that the latest empirical constraints on cosmology, from a combination of DESI, CMB and supernova data, can be accounted for if a small component of dark matter has an evolving and oscillating equation of state within $-1<w<1$. From a fundamental physics perspective, this interpretation is more appealing than an evolving phantom dark energy with $w<-1$, which violates the null energy condition.